Nymphal survival and habitat distribution of Ixodes scapularis and Amblyomma americanum ticks (Acari: Ixodidae) on Fire Island, New York, USA

The distribution and survival of Ixodes scapularis and Amblyomma americanum were studied in deciduous and coniferous wooded habitats and in open habitats on Fire Island, New York, USA. The survival of nymphal I. scapularis in field enclosures was greater in forests than in open habitats, suggesting that greater survival contributes to the higher tick population in the woods. The nymphs of each species were more common in deciduous thickets (predominantly Aronia arbutifolia and Vaccinium corynbosum) than in coniferous woods (mostly Pinus rigida) in most but not all years. Larval I. scapularis were more common in coniferous sites in 1994, while the same ticks, as nymphs, were more common in deciduous sites in 1995. The survival of the nymphs was not consistently greater in either the deciduous or coniferous woods. Therefore, factors other than nymphal survival (e.g. larval overwintering survival and tick movement on hosts) probably influenced the relative nymph abundance in different forest types. Overall, the survival of A. americanum was far higher than that of I. scapularis.     

A quantitative comparison of two sample methods for collecting <Emphasis Type="Italic">Amblyomma americanum</Emphasis> and <Emphasis Type="Italic">Dermacentor variabilis</Emphasis> (Acari: Ixodidae) in Missouri

In studies of tick communities, sampling methodology may influence observed patterns. The objective of this study was to compare two sampling methods, dragging and dry ice baiting, in two habitats to assess abundance of off-host ticks. Tick communities were monitored from March to December in a forested and an old-field habitat in northeast Missouri. In each habitat, eight drag and eight dry ice bait samples were collected every 2 weeks on a permanent grid. The most common ticks collected were all life stages of Amblyomma americanum L. and adult and larval Dermacentor variabilis Say. Capture data was analyzed to determine if there were differences due to sampling method, habitat or an interaction for each life stage of each species across the entire monitoring period. Data indicate that there were differences in the methods. Significantly more A. americanum nymphs were captured by bait sampling. Dragging captured significantly more larval A. americanum. Significantly more larval and nymphal A. americanum and larval D. variabilis were caught in the forest, whereas significantly more adult D. variabilis were collected in the field. Significant interaction between site and method was found for A. americanum adults and D. variabilis larvae. These differences are likely due to differences in behavior among species and developmental age that interact with microclimate. These data indicate that community monitoring studies should use multiple sampling methodologies to avoid bias. While comparing these methods, the first documented collection of off-host Ixodes scapularis Say in Adair County, Missouri was made.     

Pathogenicity of <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> (Deuteromycetes) and permethrin to <Emphasis Type="Italic">Ixodes scapularis</Emphasis> (Acari: Ixodidae) nymphs

Effectiveness of the entomopathogenic fungus Metarhizium anisopliae, for controlling nymphal Ixodes scapularis, was tested in laboratory and field trials. In the laboratory, M. anisopliae (Metschnikoff) Sorokin strain ESC1 was moderately pathogenic, with an LC₅₀ of 10⁷ spores/ml and induced 70% mortality at 10⁹ spores/ml. In a field study, however, 10⁹ spores/ml M. anisopliae did not effectively control questing I. scapularis nymphs, and significant differences were not detected in pre- and post-treatment densities. For nymphs collected and returned to the laboratory for observation, mortality was low in treatment groups, ranging from 20 to 36%. To assess whether a chemical acaricide would synergistically enhance pathogenicity of the fungus, we challenged unfed nymphal I. scapularis with combinations of M. anisopliae and permethrin, a relatively safe pyrethroid acaricide, in two separate bioassays. Significant interactions between M. anisopliae and permethrin were not observed, supporting neither synergism nor antagonism.     

Field and climate‐based model for predicting the density of host‐seeking nymphal Ixodes scapularis,an important vector of tick‐borne disease agents in the eastern United States

Aim Ixodes scapularis is the most important vector of human tick‐borne pathogens in the United States, which include the agents of Lyme disease, human babesiosis and human anaplasmosis, among others. The density of host‐seeking I. scapularis nymphs is an important component of human risk for acquiring Borrelia burgdorferi, the aetiological agent of Lyme disease. In this study we used climate and field sampling data to generate a predictive map of the density of host‐seeking I. scapularis nymphs that can be used by the public, physicians and public health agencies to assist with the diagnosis and reporting of disease, and to better target disease prevention and control efforts. Location Eastern United States of America. Methods We sampled host‐seeking I. scapularis nymphs in 304 locations uniformly distributed east of the 100th meridian between 2004 and 2006. Between May and September, 1000 m² were drag sampled three to six times per site. We developed a zero‐inflated negative binomial model to predict the density of host‐seeking I. scapularis nymphs based on altitude, interpolated weather station and remotely sensed data. Results Variables that had the strongest relationship with nymphal density were altitude, monthly mean vapour pressure deficit and spatial autocorrelation. Forest fragmentation and soil texture were not predictive. The best‐fit model identified two main foci – the north‐east and upper Midwest – and predicted the presence and absence of I. scapularis nymphs with 82% accuracy, with 89% sensitivity and 82% specificity. Areas of concordance and discordance with previous studies were discussed. Areas with high predicted but low observed densities of host‐seeking nymphs were identified as potential expansion fronts. Main conclusions This model is unique in its extensive and unbiased field sampling effort, allowing for an accurate delineation of the density of host‐seeking I. scapularis nymphs, an important component of human risk of infection for B. burgdorferi and other I. scapularis‐borne pathogens.     

Control of Ixodes scapularis and Amblyomma americanum Through use of the ‘4-poster’ Treatment Device on Deer in Maryland

Deer self-treatment devices (‘4-posters’) were evaluated for their efficacy in reducing populations of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum. At each of three locations in Maryland, 25 ‘4-posters’ were operated in study areas of approximately 5.18 km². Populations of host-seeking ticks were monitored by flagging of treated areas and similar untreated control areas without ‘4-posters.’ From 1998 to 2002 the percent mortalities achieved were 69, 75.8 and 80 at the three study sites infested with I. scapularis nymphs, and 99.5 and 95.3 for A. americanum nymphs at the two sites where this species occurred. This revised version was published online in July 2006 with corrections to the Cover Date.     

A comparison of methods for sampling the deer tick,Ixodes dammini,in a Lyme disease endemic area

The purpose of this study was to compare the trapping and examining of mice, drag sampling, and CO₂-baited traps for their ability to detect the presence and abundance of immature deer ticks,Ixodes dammini, in a Lyme disease endemic area in southern New York State. Eight study sites were sampled 14 times between 28 May and 31 August by setting 49 live-traps, four CO₂-baited traps, and drag sampling 500 m². A total of 1540 nymphs and 3079 larvae was collected during the study. Drag sampling collected the most nymphs (705), while more larvae were recovered from CO₂-baited traps (1105). Comparisons among the methods showed a significant difference in the numbers of both larval and nymphal ticks collected (P<0.01). There was a positive correlation between the numbers of nymphs collected by drag sampling and CO₂-baited tick traps (r _s=0.83,P<0.05), and between the numbers of larvae collected by drag sampling and mouse trapping (r _s=0.75,P<0.05). These results suggest that drag sampling would be the single most reliable method for quantitatively sampling immatureI. dammini populations in a Lyme disease endemic area.     

Comparison of novel and conventional methods of trapping ixodid ticks in the southeastern U.S.A.

Tick‐borne disease surveillance and research rely on resource‐effective methods for tick collection. This study compared the respective performances of several trapping methods in a mixed grassland–forest habitat in western Tennessee. To test for temporal differences in effectiveness, sites were sampled monthly (April–August 2013) using dry ice, dragging, flagging, sweep netting, carbon dioxide (CO₂) dragging and CO₂ flagging methods. To evaluate the effect of habitat on method effectiveness, four methods (dragging, CO₂ dragging, CO₂ flagging and dry ice) were compared in four habitat types (bottomland deciduous, upland deciduous, coniferous and grassland) in June 2014. In the temporal comparison, ticks were found to be most abundant in April and May, and there was a significant sampling period and method interaction, such that method effectiveness varied across sampling period. Sweep netting was significantly less effective than the other methods. In the habitat comparison, dry ice trap collections represented the most effective method in upland deciduous and coniferous habitats. Flagging using CO₂ was significantly less effective than CO₂ dragging and dragging in bottomland deciduous habitats. The success of the various collection methods did not differ significantly within grassland habitats. Overall, dry ice trapping and dragging were the most effective methods for tick collection across time and habitat.     

Kinetics of ingested host immunoglobulin G in hemolymph and whole body homogenates during nymphal development of Dermacentor variabilis and Ixodes scapularis ticks (Acari: Ixodidae)

Patterns in the utilization of host immunoglobulin G (IgG) during nymphal development differed between Dermacentor varibilis (Say) and Ixodes scapularis Say ticks. In unfed nymphs of D. variabilis, host IgG was readily detectable in both hemolymph and whole body homogenates. In unfed nymphs of I. scapularis, host IgG was absent in hemolymph and at very low concentrations in whole body homogenates. Host IgG in unfed nymphs was undoubtedly the remnants of IgG acquired during the larval bloodmeal that persisted through metamorphosis to the nymphal stage. In both tick species, host IgG crossed the midgut into the hemocoel during the latter phases of engorgement. Concentrations of host IgG in I. scapularis declined considerably after replete nymphs molted to the adult stage. In contrast, concentrations of host IgG in D. variabilis remained elevated throughout metamorphosis to the adult stage. When larval D. variabilis were fed on a rat, then 2 months later as nymphs on a rabbit, the rat IgG (“old IgG”) present in unfed nymphs was totally replaced by rabbit IgG (“new IgG”) within 2 d of nymphs attaching to the rabbit. Presumably, the old IgG acquired from a previous bloodmeal was secreted via saliva into the new host. This revised version was published online in July 2006 with corrections to the Cover Date.     

Tick species establishment in Oklahoma County,Oklahoma, U.S.A., identified by seasonal sampling in residential and non‐residential sites

In recent years, human tick‐borne disease occurrence has risen in Oklahoma, U.S.A., but year‐round data on tick presence in frequently used recreational areas is not widely available. In this study, ticks were collected monthly for one year at residential and non‐residential sites in a suburban area of Oklahoma County, OK, U.S.A. At each trapping site, dry ice traps were used in both woodland and grassland areas and fabric tick drags were used in grassland areas. Four species were collected from each park: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. Prior to this study, A. americanum was the only species with an established population in Oklahoma County. Consistent with this, A. americanum was collected in all months of the year and accounted for over 90% of ticks collected at each site. Based on our tick survey, we report that A. maculatum, D. variabilis, and I. scapularis, which were each collected in numbers greater than six within a single sampling occasion, are now each confirmed as established populations in Oklahoma County.     

Densities of Ixodes ricinus ticks (Acari: Ixodidae) on moorland vegetation communities in the UK

Unfed (questing) Ixodes ricinus ticks were collected by blanket dragging on a monthly basis from heather-dominated, Vaccinium-dominated and bracken-dominated vegetation communities from two different biogeographical regions of the UK (the Quantock Hills in Somerset, south west England and the North York Moors, north east England) throughout the spring and summer months of 1991 and 1992. Eighteen sites were monitored across the two regions and a total of 1920 blanket drags were carried out. Vaccinium sites showed high tick densities at all life stages, as did bracken sites. Significantly lower numbers of larval and nymphal ticks per drag were collected on heather sites than were collected on either Vaccinium (bilberry/whortleberry) or bracken sites, while similar numbers of adult ticks per drag were collected from each of the three vegetation communities. There was no significant difference between the mean numbers of any tick life stage collected on the Quantock Hills and those collected on the North York Moors on these vegetation communities or between the mean numbers of any tick life stage collected in 1991 and those collected in 1992 on these vegetation communities.     

The effects of sampling method and vegetation type on the estimated abundance of <Emphasis Type="Italic">Ixodes ricinus</Emphasis> ticks in forests

Estimating the spatial and temporal variation in tick abundance is of great economical and ecological importance. Entire-blanket dragging is the most widely used method to sample free-living ixodid ticks. However, this technique is not equally efficient in different vegetation types. The height and structure of the vegetation under study will not only determine the likelihood of a tick-blanket contact, but will also determine the rate of dislodgement. The purpose of this study was therefore to determine whether the alternative strip-blanket is more effectively in picking up ticks than the standard entire-blanket. Sampling was carried out in four forest understory vegetation types that differed in height and structure on five collection dates between April and September 2008. A total of 8,068 Ixodes ricinus ticks was collected (778 adults, 1,920 nymphs, and 5,370 larvae). The highest numbers of ticks were collected along the forest trails, where the dominant vegetation consisted of short grasses. The lowest numbers of ticks were collected in bracken-fern-dominated sites, where the vegetation seriously hampered tick sampling. Surprisingly, in each vegetation type, significantly more nymphs and adults were collected using the entire-blanket. However, the strip-blanket was more effectively in collecting larvae, especially in dense and tall vegetation.     

Different Populations of Blacklegged Tick Nymphs Exhibit Differences in Questing Behavior That Have Implications for Human Lyme Disease Risk

Animal behavior can have profound effects on pathogen transmission and disease incidence. We studied the questing (= host-seeking) behavior of blacklegged tick (Ixodes scapularis) nymphs, which are the primary vectors of Lyme disease in the eastern United States. Lyme disease is common in northern but not in southern regions, and prior ecological studies have found that standard methods used to collect host-seeking nymphs in northern regions are unsuccessful in the south. This led us to hypothesize that there are behavior differences between northern and southern nymphs that alter how readily they are collected, and how likely they are to transmit the etiological agent of Lyme disease to humans. To examine this question, we compared the questing behavior of I. scapularis nymphs originating from one northern (Lyme disease endemic) and two southern (non-endemic) US regions at field sites in Wisconsin, Rhode Island, Tennessee, and Florida. Laboratory-raised uninfected nymphs were monitored in circular 0.2 m² arenas containing wooden dowels (mimicking stems of understory vegetation) for 10 (2011) and 19 (2012) weeks. The probability of observing nymphs questing on these stems (2011), and on stems, on top of leaf litter, and on arena walls (2012) was much greater for northern than for southern origin ticks in both years and at all field sites (19.5 times greater in 2011; 3.6–11.6 times greater in 2012). Our findings suggest that southern origin I. scapularis nymphs rarely emerge from the leaf litter, and consequently are unlikely to contact passing humans. We propose that this difference in questing behavior accounts for observed geographic differences in the efficacy of the standard sampling techniques used to collect questing nymphs. These findings also support our hypothesis that very low Lyme disease incidence in southern states is, in part, a consequence of the type of host-seeking behavior exhibited by southern populations of the key Lyme disease vector.     

Improvement of field sampling methods for adult Karoo paralysis ticks,Ixodes rubicundus (Acari: Ixodidae), through addition of host odour

The responsiveness of Ixodes rubicundus ticks on questing substrates and the success of their attachment to non-living substrates were investigated. The purpose of this study was to relate responsiveness to conditions of temperature and humidity, to compare the efficacy of flagging and dragging methods to estimate the size of populations of adult I. rubicundus in the field, and to determine the possible influence of host odour on the efficacy of these methods. Responsiveness was tested under varying conditions of temperature and humidity under field conditions, and the same ticks were used to determine the duration of attachment to a flannel cloth, either impregnated with host odour from sheep wool or without it. Flagging and dragging methods were compared under laboratory conditions with cloths either treated with host odour or not. Within the range of ambient temperatures recorded during this study (7–25°C) most of the ticks (86%) were responsive. No obvious relationship between temperature, relative humidity and responsiveness of ticks was evident. Ticks remained on average 32.9 seconds (n=64) on cloth treated with host odour compared to 9.1 seconds (n=54) on untreated cloth. Flagging was 1.5–1.7 times as effective as dragging and treatment of the cloths with host odour increased the efficacy 2.4 (dragging) to 2.8 (flagging) times. The reactions of ticks to external stimuli should, therefore, be taken into account to maximize field sampling success.     

Abundance and seasonal activity of questing Ixodes ricinus ticks in their natural habitats in southern Germany in 2011

Questing ticks were sampled monthly over a period of 11 months from February, 2011 to December, 2011 at 13 sites in southern Germany using the flagging method. The ticks were identified to species, gender, and stadium. Although both I. ricinus and D. reticulatus were sampled, this study concentrated on I. ricinus, since it was the most abundant tick to be found. Additional weather data (air and soil temperature, relative air humidity, precipitation, sunshine duration) were recorded on each sampling site and the local vegetation described. A total of 14, 394 ticks was collected (7,862 larvae, 5,568 nymphs, 964 adults) and their activity was recorded in order to determine the seasonal activity pattern over different periods of the year. In contrast to the widely accepted pattern of a bimodal seasonal activity in moderate areas with a dominant peak in spring and a minor peak in autumn, a unimodal activity pattern was found for all development stages on six of the 12 sampling sites. Tick abundance was compared to weather variables. Tick host‐seeking activity was found to be significantly dependent on the temperature at ground level, precipitation, and sunshine duration as well as relative air humidity. Adult ticks showed a positive correlation with the duration of sunshine, whereas nymphs were mostly unaffected by this phenomenon.     

Tick infection rates with Borrelia Ixodes ricinus versus Haemaphysalis concinna and Dermacentor reticulatus in two locations in eastern Germany

Unfed nymphal Ixodes ricinus, Haemaphysalis concinna, and adult Dermacentor reticulatus were collected in two locations of Saxony in July and September 1991 by flagging. In July, the abundance of nymphal I. ricinus was about 2-3 times higher than that of nymphal H. concinna, a time of the year when nymphs of both species are reported to have a seasonal peak of activity. No D. reticulatus were flagged concurrently. In September, host-seeking activity of nymphal I. ricinus was again quite high as was that of adult D. reticulatus but only low numbers of nymphal H. concinna were collected. The flagged ticks were individually examined for Borrelia by an indirect immunofluorescence assay (I. ricinus: n = 414; H. concinna: n = 96; D. reticulatus: n = 116). The prevalence of Borrelia (probably B. burgdorferi) in I. ricinus varied from 12.1% to 21.0%. No borreliae were found in H. concinna. Of the examined D. reticulatus from one site (n = 97) 11.3% contained either B. burgdorferi or a related Borrelia. This may be the first finding of Borrelia in an Eurasian Dermacentor species.     

Repellency of two terpenoid compounds isolated from <Emphasis Type="Italic">Callicarpa americana</Emphasis> (Lamiaceae) against <Emphasis Type="Italic">Ixodes scapularis</Emphasis> and <Emphasis Type="Italic">Amblyomma americanum</Emphasis> ticks

Callicarpenal (13, 14, 15, 16-tetranor-3-cleroden-12-al) and intermedeol [(4S,5S,7R,10S)-eudesm-11-en-4-ol], isolated from American beautyberry, Callicarpa americana (Lamiaceae), were evaluated in laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes scapularis, and lone star tick, Amblyomma americanum. A strip of organdy cloth treated with test solution was doubly wrapped (treatment on outer layer) around the middle phalanx of a forefinger and ticks released on the fingertip. Callicarpenal and intermedeol, at 155 nmole/cm² cloth repelled 98 and 96% of I. scapularis nymphs, respectively. Dose response tests with I. scapularis nymphs showed no difference in repellency among callicarpenal, intermedeol and Deet (N,N-diethyl-3-methylbenzamide), however, SS220 ((1S,2′S)-2-methylpiperidinyl-3-cyclohexene-1-carboxamide) was significantly more repellent than the other compounds. Callicarpenal, at 155 nmole/cm² cloth, repelled 100 and 53.3% of I. scapularis nymphs at 3 and 4 h, respectively, after the cloth was treated, whereas intermedeol repelled 72.5% of I. scapularis nymphs 3 h after treatment. In comparison with the results obtained with I. scapularis, callicarpenal, intermedeol, Deet and SS220 were less effective against A. americanum. Only intermedeol and SS220 repelled significantly more A. americanum than ethanol controls at 155 nmole compound/cm² cloth. At 1,240 nmole/cm² cloth, callicarpenal and intermedeol repelled 20 and 40% of A. americanum nymphs.     

Invasion of the Lyme Disease Vector <Emphasis Type="Italic">Ixodes scapularis</Emphasis>: Implications for <Emphasis Type="Italic">Borrelia burgdorferi</Emphasis> Endemicity

Lyme disease risk is increasing in the United States due in part to the spread of blacklegged ticks Ixodes scapularis, the principal vector of the spirochetal pathogen Borrelia burgdorferi. A 5-year study was undertaken to investigate hypothesized coinvasion of I. scapularis and B. burgdorferi in Lower Michigan. We tracked the spatial and temporal dynamics of the tick and spirochete using mammal, bird, and vegetation drag sampling at eight field sites along coastal and inland transects originating in a zone of recent I. scapularis establishment. We document northward invasion of these ticks along Michigan’s west coast during the study period; this pattern was most evident in ticks removed from rodents. B. burgdorferi infection prevalences in I. scapularis sampled from vegetation in the invasion zone were 9.3% and 36.6% in nymphs and adults, respectively, with the majority of infection (95.1%) found at the most endemic site. There was no evidence of I. scapularis invasion along the inland transect; however, low-prevalence B. burgdorferi infection was detected in other tick species and in wildlife at inland sites, and at northern coastal sites in years before the arrival of I. scapularis. These infections suggest that cryptic B. burgdorferi transmission by other vector-competent tick species is occurring in the absence of I. scapularis. Other Borrelia spirochetes, including those that group with B. miyamotoi and B. andersonii, were present at a low prevalence within invading ticks and local wildlife. Reports of Lyme disease have increased significantly in the invasion zone in recent years. This rapid blacklegged tick invasion—measurable within 5 years—in combination with cryptic pathogen maintenance suggests a complex ecology of Lyme disease emergence in which wildlife sentinels can provide an early warning of disease emergence.     

Tick community composition in Midwestern US habitats in relation to sampling method and environmental conditions

The ranges of many tick species are changing due to climate change and human alteration of the landscape. Understanding tick responses to environmental conditions and how sampling method influences measurement of tick communities will improve our assessment of human disease risk. We compared tick sampling by three collection methods (dragging, CO₂ trapping and rodent surveys) in adjacent forested and grassland habitats in the lower Midwest, USA, and analyzed the relationship between tick abundance and microclimate conditions. The study areas were within the overlapping ranges of three tick species, which may provide conditions for pathogen exchange and spread into new vectors. Dermacentor variabilis (American dog tick) was found using all methods, Amblyomma americanum (lonestar tick) was found by dragging and CO₂ trapping and Ixodes scapularis (blacklegged deer tick) was found only on rodents. Proportion of each species differed significantly among sampling methods. More ticks were found in forests compared to open habitats. Further, more ticks were collected by dragging and from rodents in hotter, drier conditions. Our results demonstrate that multiple sampling methodologies better measure the tick community and that microclimate conditions strongly influence the abundance and activity of individual tick species.     

Species,developmental stage and infection with microbial pathogens of engorged ticks removed from dogs and questing ticks

Research into tick‐borne diseases implies vector sampling and the detection and identification of microbial pathogens. Ticks were collected simultaneously from dogs that had been exposed to tick bites and by flagging the ground in the area in which the dogs had been exposed. In total, 200 ticks were sampled, of which 104 came from dogs and 96 were collected by flagging. These ticks were subsequently examined for DNA of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Rickettsia spp. and Babesia canis. A mixed sample of adult ticks and nymphs of Ixodes ricinus (Ixodida: Ixodidae) and Haemaphysalis concinna (Ixodida: Ixodidae) was obtained by flagging. Female I. ricinus and adult Dermacentor reticulatus (Ixodida: Ixodidae) ticks dominated the engorged ticks removed from dogs. Rickettsia spp. were detected in 17.0% of the examined ticks, A. phagocytophilum in 3.5%, B. canis in 1.5%, and B. burgdorferi s.l. in 16.0%. Ticks with multiple infections were found only among the flagging sample. The ticks removed from the dogs included 22 infected ticks, whereas the flagging sample included 44 infected ticks. The results showed that the method for collecting ticks influences the species composition of the sample and enables the detection of a different pattern of pathogens. Sampling strategies should be taken into consideration when interpreting studies on tick‐borne pathogens.     

Diversity,ecology, and seasonality of hard ticks (Acari: Ixodidae) in eastern Croatia

The diversity of hard tick fauna was studied in different forest communities in 48 localities of eastern Croatia using the dragging‐flagging method and by hand from ten different vertebrate hosts. A total of 2,225 specimens comprising seven species in three genera were identified. Ixodes ricinus, the most abundant species (72.8% of all collected specimens) was recorded in 44 localities, followed by Dermacentor reticulatus in 19 localities, while the other five species (D. marginatus, H. concinna, H. inermis, I. canisuga, and I. hexagonus) were recorded in fewer localities. The highest ratio (67% of collected ticks) was in the adult stage with the predominance of females. The numbers of collected females, males, and nymphs of I. ricinus and H. concinna differed significantly. Ten new tick‐host associations in Croatia were recorded. Fifty‐three animals were infested with one tick species. Single species infestation with I. ricinus was found in 45.8% of animals, followed by D. reticulatus with 25.4%, D. marginatus with 10.2%, H. inermis and I. hexagonus with 3.4%, and I. canisuga with 1.7%. Coinfestation with two species of ticks were recorded in six animals. Ixodes ricinus, H. inermis, and D. reticulatus showed bimodal seasonal activity; for other species unimodal activity patterns were recorded.